Research On Torque Ripple Reduction And Speed Control Of Six-Phase Switched Reluctance Motor

In recent years, the Switched Reluctance Motor was attracted and applied widely, because of the advantages, such as simple structure, lower cost and the ability of operating stably and efficiently in harsh environments. Along with the rise of new energy industry, the electric vehicles developed rapidly. in addition, the type of motors became more and more than before. Among of them, SRM could meet the needs of current electric vehicle drive motor, because of its highly stability and excellent performance of speed adjustment. However, the fault tolerance ability of Six-Phase SRM was stronger than the traditional three-phase, four-phase, and five-phase motor, above of these, So the Six-Phase SRM has been chosen as the object of this study. Otherwise, on the one hand the serious torque ripple affected the practical application of traditional SRM. For this, the Direct Torque Control(DTC) Strategy was designed in this study in order to reduce the torque ripple. On the other hand the poor control accuracy and poor robustness of PI speed controller in conventional SRM control system influenced the effect of controlling speed. For this issues, the Adaptive Second Order Sliding Mode Controller(A-2-SMC) were designed in this study in order to achieve better effect of speed control. In the end, Simulation model of Six-Phased 12/10 pole SRM was established in this paper, as well as the feasibility and superiority of these control strategies were verified by the simulation experiment, which provided the theoretical basis of the application of Six-Phased 12/10 pole SRM in electric vehicles.The main work and results of this paper were showed as followed:1. The Six-Phased 12/10 pole SRM was established. An Ansoft mode was designed to describe the Six-Phased SRM for electric vehicles, which could get the basis data of the motor flux and torque characteristics. Then, the simulation model was constructed by Matlab/Simulink platform through importing the basis data. Simultaneously, current chopping control strategy was used to study the simulation model system initially. The result showed that, the self-constructed simulation model could reflect the characteristics of Six-Phased 12/10 pole SRM and had the flexibility of control strategy.2. Direct Torque Control(DTC) Strategy for the Six-Phase 12/10 pole SRM was designed. According to DTC,12 voltage space vectors were determined and selected, the 6/2 synthesis flux linkage change module was provided and the corresponding switching table was designed. At last the effect of the control strategy was confirmed by the result of simulation model and the comparison with CCC strategy. The result showed that, the DTC Strategy was better than CCC strategy with the ability of reducing about 66.7% of the torque ripple.3. The Adaptive Second Order Sliding Mode Controller(A-2-SMC) was designed. However, chatter problem was the biggest shortcoming of SMC. A-2-SMC was designed to overcome the defect of sliding mode chattering. Simultaneously, the problem of second order sliding mode(2-SMC) parameter selection was solved by the parameter adaptive controller, which avoids the shortcoming of the traditional second order sliding mode parameter determination should be based on the boundary of the disturbance’s derivative. At last the stability of the controller was determined by theoretical proof.4. Hybrid control scheme of Switched Reluctance Motors based on A-2-SMC and DTC was proposed. In order to improve the control effect of Six-Phase SRM, The DTC and A-2-SMC were combined, which could not only suppress the torque ripple but also improve the robustness and accuracy of the motor control system.At the same time,the A-2-SMC superior control performance was reflected by the comparison with the effect of several other controlling controllers.5. Motor Experiment System was established in this paper. According to the results of theory and simulation, there were two parts in this section: the TMS320F2812 interface circuit and the protection circuit of experimental system were designed in hardware part; the DTC control subroutine structure, A-2-SMC control subroutine structure and the PC monitoring system based on Labview were designed in software part.